Pipe-threading apparatus



B. FBUTLER.

PIPE THREADING APPARATUS.

APPLICATION FILED H114, 1911:.

Patented June 1 0, 1919.

2 SHEETS-SHEET I.

INVENTOR ATTO BUTLER. PIPE THREADING APPARATUS. APPLICATlON FILEDFEB.14. i918.

Patented Jun@ 10, 1919.

2 SHEETS-SHEET 2- l INVENTOR ATTORNE FFEC.

BENJAMIN P. BUTLER, OP GREENPIELD, MASSACHUSETTS, AssIcfNoR` TOCREENPIELD TAP AND DIE CORPORATION; A CORPORATION OP MASSACHUSETTS.

PIPE-THREADING APPARATUS.

Specification of Letters Patent.

Patented June 10, 1919.

Application filed February 14, 1918. Y Serial No. 217.053.

To all whom t may concern.'

Be it known that I, BENJAMIN F. BUTLER, a citizen of the United Statesof America, residing at Greenfield,Massachusetts, have invented new anduseful Improvements in Pipe-Threading Apparatus, ofA which the followingis a specication.

This invention relates to improvements in pipe-threading apparatus, andit has for its object to provide a simple, positive, and effectivepipe-threading apparatus fof the recession type, that is, of the typewherein the cutting dies recede from the axis of the pipe as the threadis cut from an end of the pipe toward an intermediate portion thereof,

in order to cut what is known as a taper thread. The particular objectof the invention is to provide such a pipe-threading apparatus, and onewherein two independently adjustable Controls are provided, adapted forpreliminary setting, one to predetermine the length of the thread to becut, and the other to predetermine the depth of the thread to be cut.

\ Heretofore pipe-threading apparatus capable of being preliminarilyadjusted for length of thread and depth of thread have been proposed,but have had the serious disadvantage that when preliminary adjustmentfor length of thread is made, compensating and difficult adjustment mustbe made for depth of thread, and vice versa.

' The present invention, in its essentials, involves the employment of asupport` for holding a pipe, a support for a means for cutting a threadon the pipe, one of said supports being spirally movable relative to theother, controlling means for then mov ing the cutting means radially 0fthe pipeto cut a thread of a certain taper on the pipe, meansforadjusting the controlling means to permit a. thread of a predeterminedlength to be cut, and means for adjusting thecontrolling means to cut athread of any one of several predetermined depths but all of saidcertain taper; ythe main feature of the invention being the arrangementwhereby either of the two adjusting means maybe adjusted independentlyof the other, and without disturbing the adjustment previ- Ously fixedby the other.

The invention is preferably applied to a known type of pipe-threadingapparatus in which the Cutting dies are permitted to' re- @ede kas thethreadis eut more and there,

by means of the yielding action by levers which are in slidingengagement with abutments or cams on a nut traveling on a hOllow Screwsurrounding the pipe. When the invention is applied to such a structure,a preferable embodiment thereof would include a pipe-cutting devicecomprising thread-cutting dies spaced around the pipe on an annularsupport,` levers for actuating said dies and pivoted on said supportopposite the outer ends of the dies, a hollow externally threaded screwsurrounding the pipe and carried by the die-support, a pipe clampingsupport, a nut rotatable on the pipe-clamping support and on the screw,a slide rod joining the diesupport and the nut and having two stops oneof which is adjustable, with the support and nut located between thestops, so that the adjustable stop may be set on the rod to predeterminethe limits of axial travel of the nut on the screw during a singlethreading operation, and an annulus adjustable Circumferentially of thenut and mounted thereonand carrying a plurality of outwardly radiallyprojecting cams one for coacting with each of said levers. Also,preferably the nut carries a circumferential Series of calibrations andthe annulus a coperating index; or vice versa. In short, the inventionmay be very simply expressed in relation to the known structure justdescribed, by stating that it may be, 4and is preferably, carried out bysplitting up the former nut into two parts, one of which parts remainsas the nut and carries the means for engaging the stop rod, and theother part" is formed so as to be carried by the first-mentioned partand to be adjustable thereon and carry the lever-cont-rolling abutmentor cams. I e

The invention will be more clearly understood from the followingdescription, when taken in connection with the accompanying drawingsshowing an embodiment of the invention at present preferred.

In these drawings, z

Figure l is an axial section, taken through the pipe-threadingapparatus, with certain of the parts shown in elevation, this view beinga section on the line 1-1 lof Fig. 2;V

Fig. 2 is a section on the line 2*-2 of Fig. l;

Fig. 3Y is a fragmentary view showing cer tain of the parte' of Fig; lin togp'plan; and

- lar parts throughout the several views of the drawings. n I

Thepipe to be threaded, which in Fig. 1 is Y shown to be in the courseof being threaded,

is indicated at 1.

Mounted on a support 5 are a plurality of thread-cutting chasers or dies6. There are preferably four of theseV dies, spaced -apart 90o as shownin Fig. 3. Thesedies slide in housings7 fixed on the support 5. The diesareintended to be held to the work by means of the abutment againsttheir rear ends of the short arms of the levers 8 pivoted to thehousings 7 One of these short arms is shown at 8 in F ig. 1. The longarms of these levers have cam surfaces one of which is shown at S inFig'. 1` n TheY support 5 carries a depending tubular portion 9surrounding the pipe and eX- teriially threaded'. This tubular part ofthe support 5 is screw-threadedly connected, as indicated at 9l in Fig.1, with what may be termed a nut-structure 10 (see Fig- 1) .including acage 1 provided with clamping means generally indicated at 2 (see Fig'.1.) whereby the pipe Ymay be clamped therein and centrally of thetubular part 9 of the die support 5.

The nut-structure 10 includes two removable and separately adjustableannuli- 1l and 12. The aiiiiulus 11, as shown best from a comparison ofFig. 2 with Fig. 1, is provided with two radial projections 13 bored andcounter-bored as indicated at 14. The.'

aniiulus 12, as will best be seen from a comparison of Fig. 2 with Fig.1, is provided with four abutments or cams 15, outwardly projecting,spaced apart 900. Each of these A cams 15 Vis adapted to coact with thecamV in Fig. 1, coacts with the thread of a threaded aperture 17 cutthrough the support 5. threaded end of each rod .1Gv has adjustablymounted thereon a lock nut 18. The cam carrying aniiulus 12 isadjustable'circumferentially of the annulus 11 which' carries theprojections 13, preferably by the aid of a suitable series ofcalibrations on the annulus 11 and a coperating indeX 19 on the annu'lus12, as shown in Fig. 4; and ivhei'i'the parts are thus adjusted asdesired, the annulus 12 may be locked to the anniilu's 11 by Y means ofthethumb screw 2Q shown in Fig. 2. In order that the annuli 11 and 12may be readily removed, these parts areheld in place on the nutstructure 10 by means of As shown in Figs. 1 and 8, the

an internally' threaded ring 21, screwed on Van upwardly'extendingreduced portion22 of the nut-'structure 10.

Y Before describing theY operation of theA device during the`thiead-cutting. operation, pursuant to any selected adjustment, it

should be explained Y that by circumferentially adjusting the annulus 12on the `ann nulus 11 the 'long armV of the levers 8 will be more or'less held out from the axis of the pipe, according toV theV positions ofthe cams 15 relative tosuch levers, at the com` Vmencem'ent of thethread-cutting operation,

so that tliejciitting of the rstpartofthe thread will be of greaterorless depth. Thereafter, due to the design of the cam surfaces 8, thelevers 8, coacting with the 1 selected points` on the cams'l will, asthe cams and the axes of the levers come closer together, permit thedies to recede as the cut-tino* of the thread isl proceeded with,

where y the thread will have the requiredv taper'. Itshould also beexplained, preliniiiiar'ily, Vthat tli'efunction'of tlierods 16 to limitthe amount of travel of the cams 15 away froi'ntlie aXAes ofthellevers8v before any pipe-threading operation, thereby to limit the length ofthe permissible thread. This adjustment is obtained by means of the nut18, Vwhich acts as a loclrnut after the threaded part of the rod 16 hasbeen properly adjusted relative to the threaded bore 17 of the support5. Thus the apparatus shown in Fig. lhas been set so that at thecommencementV of the threading operation shown, the header fixed stop 28Von tli'e rod 16 of Fig. 1 was in the counter-bored part of theaperturela; the completion of the' thread of course occurring when thecams 15 reach the limit oftheir possible movement toward the axes ofthe'levers 8. Operation: A j First, as just described in the secondprecedingV paragraph, the` rods 16 arefadjusted relative to the support5 andthev lock nuts 18 tightened to lock thefrods in the selectedadjustment, to preliminar-ily set the threading apparatus for thecutting of a thread of a predetermined lengtlnand the annulus 12 isadjusted circumferentially of the annulus 11 to set the cams 15 sothat-a certain point on the curved outer surface of each cam iscontacted with the cam surface 8 of the coacting lever 8, tovpreliminarily adjustthe 'apparatus for the cutting of a threadof apredetermined depth. VTo make thislast adjustment, the' calibrations andindex shown in Fig. `@may conveniently beV uti'- lized. Finally', thethumb screw' 20 of Fig. 2 is tightened.. The pipe 4 to'bethreaded isYinserted into the nut-structure 10 and clamped within the cage 1 bymeans of the inserted in the sockets 5 carried by the member 5.Themember 5 is therebyrotated and spirally advancedrelative tothenut-structure 10 and the' pipe 4 clamped therein, thetubular portion 9ofthe support 5 screwing down into the Vcagewl of thev nut-structure 10.This rotating'rand advancing movement of the member' "5," at the sametime rotates the annuli 11` and' 12 on the nut-structure10,`by"means ofthe' rods 16, these rods serving to holdthe member l5 and the annuli 11and12 to common'quantitative rotation. Thereby` the'fsele'cted point onthe curved' outersurface of each cam 15 remains'in contactingrelationwith th'e cam surface 8 of itslfcoacting lever8. The "rods 16,@howeverjbeing smaller in diameter than the apertures 14, `do notl'interfere with the 'descent of the` 'axes'y of the levers 8 towardvthe cams'15,and as ta rei sult,\as the cuttingA of thethread'progresses, thecams 15 come closer andccloser lvtothe axes offthelevers 8 and-thereby permit the recession of the dies 6 away from theaxisof the pipe i to cut' the" selected taper .thredL The parts abutandp'revt `furthr descent of the axes of the levers 8 toward the cams 15at the instant when thethread is com-` pleted to the predeterminedlength.

The deviceswhereby the threadedcon# nection 9 is provided between thetubular part 9 of the support 5 and the nut-structure l0 form no part ofthe present invention, and therefore have not been previously described,as they have been used heretofore and are believed to be well-known inthe art. A brief description of such devices, however, mayadvantageously be set forth at this point. It will be noted from Fig. 2that the nut-structure 10, just below the annular seat 10 (Fig. 1) forthe annulus 11, is hollowed' out, as indicated at 27, Figs. 1 and 2. Atdiametrically opposite points, as indicated in broken lines in Fig. 2,the wall 10 of the nut-structure 10 is transversely slotted toaccommodate radially slidable threaded segments 28. One of thesesegments 28 is shown clearly in cross section 1n full lines in Fig. 1.As shown, each segment 28 is recessed in its outer face for thereception of a pin-held' leaf spring 29, tending to hold the segmentretracted so that its threaded inner face is out of engagement with theexternal threads of the tubular part 9 of the support 5. Slidablymounted on the annular surface 102 (see Fig. 1) of the nut-structure 10,is an annulus 30 carrying two cams 31, each adapted, when the annulus 30is turned on the nut-structure 10 and relative to the annuli 11 and 12,to force one of the segments 28 against the tendency of the spring 29 ofsuch segment, into threaded engagement with the tubular part 9 of thesupport 5. The parts are so arranged that the annulus 3() may be easilyturned in Vone direction, to permit the segments 28 to withdraw fromthreaded engagement with the tubular part 9of`the support 5, or in theopposite direction, 'to 'force the segments 28 into threaded engagementwith said part 9; irrespective of the' adjustment of the annulus 12 onthe annulus 11,or of therelative positions of the cams 15 and the axesof the levers 8. The annulus `30 is provided with a plurality ofdepending handle-extensions 30 as shown inT Figs. 1 and' 2. The presenceof the parts just describedpermits, after the completion of'a threadingoperation onone pipe, the parts `to'be reset with the head 23 of eachrod 16 seated in the counter-bored part of theaperture 14, in readinessfor the cutting of a thread on asecond pipe. Of course the annulus 30 isturned to release the segments 28 from the tubular part 9 of the support5 to reset the apparatusfor a second threading operation,and the annnlus3() is moved in the-'opposite direction to rengage the segments 28 withthe said part 9 just before thefzcommencement of thesecond threadingoperation. l

"I claim: r

1; fIn' pipe threading apparatus, the combination comprising a workholder, a die head inscrew-threaded engagement therewith, die actuatinglevers mounted on said head, a member mounted on said work holderrotatable with said head and restricted against aXial movement on theholder and a cam plate mounted on said member in actuating engagementwith said levers.

2. In pipe threading apparatus, the combination comprising a workholder, a die head in screw-'threaded engagement therewith, dieactuating levers mounted on said 105 head, a member mounted on said workholder rotatable with said head and restricted against axial movement onthe holder, a cam plate mounted on said member in actuating engagementwith said levers provided with cam surfaces for setting the levers ininitial position for the desired depth of cut.

3. In pipe threading apparatus, the combination comprising a workholder, a die head in screw-threaded engagement therewith, die actuatinglevers mounted on said head, a cam member rotatably mounted on said workholder and restricted against aXial movement thereon and having its camsurfaces in actuating engagement with said levers, driving pinsslidingly interconnecting said cam member and the die head to causethese members to rotate together while permitting relative aXialmovement, and adjustable means on said pins for limiting the movement ofthe head from the cam mem- 4. In pipe threading apparatus, 4thecombination comprising a work holder, a die head in,screw-threadedengagement there- A' with, die actuating levers mounted onsaid head, a member rotatably mounted on said Vin;

work holder and restricted against axial movement thereon, anadjustable-stop Vconnection between .said member and head forpredetermining the' length of thread, and a cam plate mounted on andcircumferentially adjustable on said member in actuating engagement withsaid levers.

6. In pipe threading apparatus, the combination comprisingthread-cutting dies,

levers for actuating said dies, a support on which said dies are movablymounted and onvwhich said leversare pivoted, a screw carried by saidsupport, a second support adapted to be clamped to the pipe, a nut onthe second support engaging the said screw, a

stop motion connection Vbetween the first support and the nut structureadjustable to predeterminethe limitsof axial travel of t-he firstsupport with respectto-the'second, and a mem-ber adjustably mounted onthe nut and carrying a camV for coactingwith one of said levers. Y -l 7.In pipe threading apparatus,the combination comprising thread-cuttingdies, levers for actuating said dies, jasupport on which said dies are`movably mounte'd'and on which said levers'are pivoteda Vscrew carriedby said support, a second support aufV f adapted to be clamped to thepipe, a nut 1 on the second support engaging theV said screw, a stopmotion connection between 'theV first support and the nut structureadjustable to predetermine the limits of axial travel of the firstsupport with respect to the second, and an annulusadjustable cir`Y Y'cumferentially oit' thenut and carrying a plurality of outwardlyradially Vprojecting cams one for coacting With VeachV of said levers.

In testimony Y name to this specification.`

Brnaniiuii-N r; BUTLER.v

Copies of this patent may be obtained for five cents each,- byaddressing the Commissioner of Patents,

Washington, D. 0.

whereof I have signed myY j Y

